Diverse Cell Types, Circuits, and Mechanisms for Color Vision in the Vertebrate Retina.
Diverse Cell Types, Circuits, and Mechanisms for Color Vision in the Vertebrate Retina.
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DOI：
10.1152/physrev.00027.2018
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发表时间：
2019-07
影响因子：
33.6
通讯作者：
W. Thoreson;D. Dacey
中科院分区：
文献类型：
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作者：
W. Thoreson;D. Dacey
提取关于波长和颜色的信息的突触相互作用开始于脊椎动物视网膜中的三类光敏细胞：低光水平下的视杆光感受器、光谱敏感性不同的多种类型的视锥光感受器和含有黑视素的固有光敏神经节细胞。当光感受器与它的邻居分离时，光感受器将光子通量与波长混淆，因此光感受器本身不提供关于颜色的信息。视网膜已经进化出复杂的颜色对抗电路，通过比较不同类型的感光器的活动来提取波长信息，这些感光器广泛地调谐到可见光谱的不同部分。我们回顾有关电路机制介导的对手在一系列物种的相互作用的研究，从四色鱼与不同颜色的对手细胞类型的常见的二色性哺乳动物，锥细胞的局限性的一个子集的专门电路。与哺乳动物不同的是，灵长类动物利用新的策略重新发明了三色色觉，将额外的色素基因进化到支持高分辨率视觉的中央凹结构和电路中。当只有视杆细胞活跃时，在暗视光水平下色觉是不存在的，但是视杆细胞与视锥细胞信号相互作用以影响在中间视觉光水平下的色觉。最近的证据表明，黑视素介导的信号，已被确定为设置昼夜节律的底物，也可能影响颜色感知。我们考虑可能介导这些相互作用的电路。虽然锥细胞的能力是一个相对简单的神经计算，但它已经在脊椎动物中通过各种尚未完全理解的神经机制来实现。
Synaptic interactions to extract information about wavelength, and thus color, begin in the vertebrate retina with three classes of light-sensitive cells: rod photoreceptors at low light levels, multiple types of cone photoreceptors that vary in spectral sensitivity, and intrinsically photosensitive ganglion cells that contain the photopigment melanopsin. When isolated from its neighbors, a photoreceptor confounds photon flux with wavelength and so by itself provides no information about color. The retina has evolved elaborate color opponent circuitry for extracting wavelength information by comparing the activities of different photoreceptor types broadly tuned to different parts of the visible spectrum. We review studies concerning the circuit mechanisms mediating opponent interactions in a range of species, from tetrachromatic fish with diverse color opponent cell types to common dichromatic mammals where cone opponency is restricted to a subset of specialized circuits. Distinct among mammals, primates have reinvented trichromatic color vision using novel strategies to incorporate evolution of an additional photopigment gene into the foveal structure and circuitry that supports high-resolution vision. Color vision is absent at scotopic light levels when only rods are active, but rods interact with cone signals to influence color perception at mesopic light levels. Recent evidence suggests melanopsin-mediated signals, which have been identified as a substrate for setting circadian rhythms, may also influence color perception. We consider circuits that may mediate these interactions. While cone opponency is a relatively simple neural computation, it has been implemented in vertebrates by diverse neural mechanisms that are not yet fully understood.